Drill bit



Aug. 18, 1931. J C, STOKES 1,819,850

DRILL BIT Filed Oct. 19, 1929 ATTORNEYS.

Patented Au l is, 1931 UNITED STATES JOHN C. STOKES, OF HOUSTQN, TEXASDRILL m Application filed October 19,

This invention relates to improvements in drill bits anda method ofconstructing the same. 7

In conventional drill bit construction, it is ordinary practice toattach the blade to the bit body by means of bolts. The bolts sometimeswork loose and permit the blade to vibrate upon the body, resultingsometimes in the destruction of the bit structure, and inefiiciently'performing the drilling opera tion. A usual type of bit constructionusing a fish-tail blade, is to provide a slot 'lon itudinally at thelower end of the bit bo y, wherein the blade fits,- and is secured bytransverse boltsi The disadvantages above mentioned are also present insuch-structure. To overcome them'I have provided a bit structure whereinthe 'body receives the bit blade in a bolted relation within the slotthereof; a suflicient clearance being provided between walls of the slotand the blade for receiving a metal which is fusible at a lowertemperature than the material of the bit body or blade, to provide atight anchoring fit of the blade in the bod A further ob ect 'of theinvention is the provision of an improved drill bit construction asabove mentioned, with the addition of transverse anchoring pins securedto the v bit blade in'a relation to be anchored within the bit body, bythe easily fusible metal, in an elficiently anchored relation.

Other objects and advantages of this invention will be apparent duringthe course of the following detailed description.

In the-drawings,-wherein for the purpose of illustration is shown only apreferred embodiment of the invention,

Figure 1 is a sectional view taken longitudinally of the bit structure,showing 'more particularly the initial assemblage operation of thefish-tail blade. in the bit body,

prior to receivingthe fusible metal for anchoring purposes.

Figures 2 and 3 are sectional views taken substantially on theirrespective lines in Fig-' ure 1 of the drawing.

Figure 4 is a view of the bit construction showing it assembled upon adrill stem.

192$Seria'l No. 400,952.

Figure 5 is a sectional view taken substantially on the line'5--5 ofFigure 6.

Figure 6 is a view similar to Figure 1, with the bit blade and otherdetails anchored in place in the body by means of the fusible metal. I

. Figure 7 is a sectional'view taken substantially on the line 7. 7 ofFigure 6.

In the drawings, wherein similar reference characters designatecorresponding parts 6b throughout the several "views, the letter A. maygenerally designate the improved bit assemblage, as shown in Figures 4and 6, which includes the bit body B, receivin the blade C in ananchored relation B,bymeansD.

The main body part B preferably includes the lower thin, but, relativelywide part 10, having an upwardly tapered externally; screw threadedcoupling portion or shank 11 thereon, which is adapted for detachablethreading in a quick release or attaching re lation within a screwthreaded socket 12 provided in the lower end of the drill line section13, asshown in Fi ure 4. The body 10 of the main body part B is providedwith a slot 20, opening at-the lowersurface'21 thereof, and extendingfrom side to side across the width of said body part 10, as is shown inFigures 1 and 2 of the drawings. This slot so 20 may be of any depthlongitudinally ofthe main body B, and it is adapted to receivethe upperflat portion 25 of the fish-tail bit 'blade C, which may be of usualconstruction, hav ing the lower bit ends 26 thereon. The body 25 of theblade structure C is provided with a transverse centrally locatedpassageway or opening 28 therethrough, and at each side ofv the opening28 there are also provided ta-K pered transversely extending openings29, which taperin the same relation from one face of the body 25 to theother face thereof,

as is well shown in Figure 2 of the drawing.

, The bifurcated lower endofthe main body B is provided with atransverse passa eway' 31, intersecting the slot 20 about midway betweenthe side edges of the said main body B, as shown in Figure 2, whichreceives a detachable bolt 32; the shank 33' thereof ex"- tending thruthe aperture .28 of the blade 0 to on the ody 65 hold the latter] Thehead 34 of the bolt 32 of course rests against one face of the body B,and the opposite screw threaded end receives a detachable nut 35 heldagainst re- 5 moval by a cotter pin 36.

' The bifurcated lower end of the main body B, at opposite sides of thepassageway 31, and in alignment with the tapered opening 29 of the bitblade, when the latter is assembled in the slot 20, are provided withtransverse openings. As shown in Figure 2, the depending flanges, atopposite sides of the slot 20, for each tapered opening 29, are provided with openings 39 and 40; the former being tapered divergently fromthe outer face 41 of the'respective flange of the body B in which theyare provided, towards the slot 20. The opening 40 may be of uniformdiameter. When the blade C is in position, the openings 29, 39 and 40axially align.

Preferably solid tapered anchor pins 45 are driven into the taperedopenings 29 of the blade construction C, after the latter is assembledand held in place in the slot 20 by the bolt 32; the said pins 45 beingentered through the openings 39, with their smaller ends first, so thatwhen driven firmly into the tapered openings 29 the smaller andv largerends of the tapered pins 45 will project beyond opposite sides of theblade body into the openings 40 and 39 respectively, as shown in Figure2; said pins 45 being only of such length that the ends thereof will notproject beyond the outer faces of the main body portion in which theblade is positioned, as shown in Figure 2.

It is to be particularly noted that no machining of the inside surfacesof the slot 20, nor of the openings through the main body or blade arenecessary, nor are the opposite faces of the blade shank machined.Rather, they are left roughened. Clearances are provided between thefacing surfaces of the.

blade O, and the main body B, and also between the extension ends of thepins in the openings 39 and 40. In these clearances,

after assemblage of the parts to the extent above described, there ispoured molten metal, which is fusible at a temperature less than thetempering heat of the main body or blade. Such metal may be ordinarysolder,

babbitt, or Monel metal of w 11 known char acteristics. All of thecleara ces are filled to \the extent shown in Figures 5, 6 and 7, forfirmly anchoring the bit blade in the main body B; the fusible metalfilling the interstices between the extension ends of the pins 45, andthe openings of the main body in which they extend. In this connectionthe 69 taper of the larger end of the pin 45 in the tapered openings 39prevents the accidental removal of the pins 45, since there is a wedgefit of the fusible metal at this location, as is quite evident fromFigures 6- and 7 of the drawings. The fusible metal is generallydesignated at 50 in the drawings. Where the fusible metal outlets on theexposed faces of the blade or main body, the same is chipped or machineflush with the adjacent surfaces.

In some instances, where water courses are provided longitudinally ofthe body of the bit structure, it may be necessary to protect such watercourses against being sealed by the fusible metal. To this end, thedrawings show longitudinally sloping water courses outletting at theupper end of the coupling shank 11 of the body B and also at the lowerend of the bodyB at opposite sides of the 'slot 20, for depositing wateror lubricating or washing fluid from the passageway of the drill stem 13onto the blade C, for well known purposes. To prevent sealing of thesewater courses, since in some instances they may be cut by the openings39 or 40, as shown in Figure 2, it is intended to place hollow tubestherethrough, the exterior surfaces of which clear the walls through thebody B, and in this clearance some of the fusible metal shown at 61 inthe drawings isplaced, either due to the placing of the fusible metal 50above described, or in an aux iliary operation; thus insuring that thetubing 60 will prevent the water courses from being sealed; the tubing60 extending from end to end of the body B.

From the foregoing description of the invention it is readily apparentthat an improved article and method has been provided,

which will prevent the bolts of bit blades from Working loose, insuringthat the blade will be attached to the main body against liability ofloosening during a drilling operaporting body having a socket thereinwithtransverse openings intersecting at opposite sides of the socket, ablade having a transverse opening therein, an anchor pin secured in thetransverse opening of the blade and extending at opposite sides of theblade through the socket and into the openings of p the body whichintersectthe socket to prevent direct pullremoval of the blade from thesocket in the body,'the blade and its anchor pin fitting in the slot andopenings of the body with clearances, and a fusible bonding materialcapable of withstanding the usual drilling shocks filling saidclearances and anchoring the bladeand its pin rigidly in the body.

2. In a device of the class described a supporting body having a sockettherein with transverse openings intersecting at opposite sides of thesocket, a blade having a transverse opening therein, an anchor pinsecured.

in the transverse opening of the blade and extending at opposite sidesof the blade through the socket and into the openings of the body whichintersect the socket to prevent direct pull removalof the blade from thesocket in the body, the blade and its anchor pin fitting in the slot andopenings of the body with clearances, a fusible bonding material capableof withstanding the usual drilling shocks filling said clearances andanchoring the blade and itspin rigidly in the'body, said anchoringmaterial being metal fusible at a lower temperature than the material.of the bodyor its anchor pin or the blade.

3. 'In a device of the class described a body having a socket thereinwith roughened walls, a blade having its outer surfaces roughened andfacing the roughened walls of the socket in spaced relation therewith,and a fusible material capable of withstanding the usual drilling shocksanchored in spaces between the roughened faces of the' blades and wallsof the socket forrigidly anchoring the blade in said socket.

4. In a device of the class described a body having a socket thereinwith roughened walls, a blade havin its outer surfaces roughened andfacing the roughened walls of the socket in spaced relation'therewith, afusible material capable of withstanding the usual drilling shocksfilling the spaces between the roughened faces of the blade and walls ofthe socket for rigidly anchoring the blade in said socket, said fusiblematerial being metal which is fusible at a lower temperature than thetempering heat of the blade or body.

5. In a device of' the class described a body having a socket thereinwith roughened walls; a blade having its outer surfaces roughened andfacing the roughened walls of the socket in spaced relation therewith, a

fusible material capable of withstanding the usual drilling shocksfilling the spacesbetween the roughened faces of the blade and walls ofthe socket for rigidly anchoring the blade in said socket, said fusiblematerial being metal which is fusible at a lower temperature than thetempering heat of the blade or body, and an anchoring pin transverselyextending through the body and blade and secured thereto to preventpulling of the blade from the body.

6. In a drill bit construction a body having a socket opening at thelower end thereof and transverse openings through the-body whichintersect the socket, and a fusible metal capable of withstanding theusual drilling shocks in the socket between the blade and socket wallsand in the openings for rigidly seatingthe extensions therein.

secting the socket, a blade loosely seated in f the socket havingextensions at'opposite sides thereof projecting into the openings whichintersect the socket, a fusible metal capable of withstanding the usualdrilling shocks in the socket between the blade and socket walls and inthe openings for rigidlyv seating the extensions therein, one of saidextensions of the blade being tapered in one direction and the openingof the body in which it seats being tapered in an opposite directionwhereby to anchor the same in a wedging relation in the fusible metalbetweenithem.

8. In a drill bit structure of the class described. a body havingasocket, a blade for loosely seating in the socketin spaced relasides ofthe'socket in loose relation in said body openings, and a fusible metalcapable of withstanding the usual driling shocks filling the spacesbetween the alls of the socket and the blade and in the openings of thebody between the walls thereof and the ends of said'pin.

9. In a drill bit structure a body, having a socket at the lower endthereof, a blade for fitting in the socket loosely, a transverse boltconnecting the blade upon the body in seating relation in said socket,anchor pins rigid with the blade intersecting the body' across saidsocket, and fusible metal ca able of withstanding the usual drillingshoe s filling the interstices between the blade and socket and aboutthe anchor pins.

l0. In a drill bit structure a body having a ing relation in saidsocket, anchor pins rigid with the blade intersecting the body acrosssaid socket, fusible metal capable of withstanding the usual drillingshocks filling the interstices between the blade and socket and aboutthe anchor ins, said body havin passages therethroug protecting tubesfitting 1n spaced relation. in the passages and fusible metal anchoringthe tubes rigidly in the passages to providebwater courses.

11. In a drill bit construction the combination' of a holder-having aslot opening at the 1 lower end thereof and opening at a side thereof,a-drilling blade disposed within said a slot and movable into the slotor out of the. slot through the side opening of the slot upon theholder, m'eans positively connecting the blade with the holder againstdropping from said slot, the blade where it fits in said slot havingcertain clearance spaces between the same and the walls defining theslot, and a fusible bonding material cast in'said clearance spaces andfirmly anchoring the blade fixedly in the holder against vibration.

12. In a drill bit construction the combination of a supporting holderhaving the lower end thereof bifurcated to provide a bottom opening slotextending transversely across said holder and opening at opposite sidesthereof, and a drilling blade having a portion thereof disposed withinsaid slot so that the sides of said portion extend beyond the sides ofthe holder exteriorly of the slot, means positively connecting the bladeupon the holder to prevent dropping of the blade by gravity from theholder when in operating position, and metal having a fusion point lowerthan that of the blade or holder cast in the slot between the portion ofthe blade which is in the slot and the walls of the holder defining saidslot and firmly anchoring said blade upon the holder to preventvibration thereof as an incident of drilling.

13. In a drill bit construction the combination of a holder having asocket opening at the lower end thereof, a drilling blade loosely seatedin the socket, interfitting portions upon the blade and socketconnecting the blade to the holder against dropping therefrom when thesame are in drilling position, and a readily fusible metal cast in thesocket between the blade and socket walls and firmly anchoring the bladeto the holder for preventing vibration of the blade in the holder duringdrillmg.

14; In a drill bit construction the combination of a holder having asocket opening at the lower end thereof, a drilling blade loosely seatedin the socket, interfitting'portions upon the blade and socketconnecting theblade to the holder against dropping therefrom when thesame are in drilling position, a readily fusible metal cast in thesocket between the blade and socket walls and firmly anchoring the bladeto the holder for pre venting vibration of the blade in the holderduring drilling, and a retaining bolt extend- 'ing transversely throughthe holder and blade for supporting the latter upon the holder. C.STOKES.

